Praia Grande (approx. 250,000 inhabitants) is part of the metropolitan region around the Brazilian port of Santos. Its official status is that of a coastal health resort. This is something the city wanted to live up to and was having new sewers constructed. For years the sewage had been directly led across the beach into the ocean. The city decided on having a new sewage treatment plant. An underground outflow line was planned to direct the treated sewage far out into the open sea.
A Herrenknecht type AVN1500TB machine was used to bore the section (726 meters long) from the beach through sandy groundwater to the open sea. For the first time on Latin America, a sea outfall was built by pipe jacking. At the end of tunnelling the machine was recovered from the sea from a pontoon. Two more sewage tunnels - each approx. 700 meters long - were bored using the same machine to complete the overall project. All three drives were supported by an experienced Herrenknecht team on the jobsite.